JP2013189326A - Method for manufacturing cover glass for electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a cover glass for an electronic device, which can reduce the manufacture cost of a cover glass for an electronic device (hereinafter, called a cover glass) good in dimensional accuracy.SOLUTION: A method for manufacturing a cover glass for an electronic device including an etching step of dissolving a platy glass along a processing pattern to obtain a glass substrate in a shape of a cover glass for an electronic device includes a non-photosensitive resist layer formation step of forming a non-photosensitive resist layer composed of a material having non-photosensitivity and etching resistance on a principal surface of the platy glass so as to cover at least a part of a non-dissolving region in the etching step, a photosensitive resist layer formation step of forming a photosensitive resist layer on the principal surface of the platy glass so as to cover a dissolving region in the etching step and adjoin the non-photosensitive resist layer, a patterning step of exposing and developing the photosensitive resist layer to thereby form the processing pattern on the photosensitive resist layer, and the etching step carried out after the patterning step.

Description

  Includes a cover glass for a portable device used as a display member for a portable device (portable electronic device) or a cover member for an internal substrate, and a cover glass for a touch sensor used as a cover member for the internal substrate in a touch sensor such as a pointing device. The present invention relates to a manufacturing method and a manufacturing apparatus for a cover glass for electronic equipment.

  For example, a cover glass for a portable device is used mainly for protecting a display screen, a circuit board, and the like of the portable device as an electronic device. In recent years, cover glasses for mobile devices having various shapes and functions have been produced in order to correspond to the casings and display screens of mobile devices having various shapes in addition to thinning and high functionality of the mobile devices.

  For example, when producing a cover glass for a portable device having a voice input / output hole for a speaker or microphone provided in the vicinity of the display screen of the portable device, the main surface of the plate glass that is the base material of the cover glass for the portable device On the other hand, etching is performed after masking corresponding to the hole pattern. Thereby, the hole of a desired shape can be formed in the cover glass for portable devices.

  As a method for masking glass such as plate glass, for example, a screen printing method, a laminate film processing method (hereinafter, film sticking method), a resist coating photolithography method, and the like are known (Patent Document 1). ). Here, the film sticking method is a method in which a masking film provided with an adhesive layer on one side is formed into a desired pattern, and this masking film is attached to the surface of glass. The resist coating photolithography method is a method of forming a desired pattern by applying a resist layer made of a photoresist (photosensitive resist) to the surface of glass and then performing exposure and development.

JP 2006-182644 A

  However, when masking is performed using a film sticking method, it is difficult to form a fine pattern, so holes and grooves that require high dimensional accuracy (for example, about 5 to 20 μm) are formed. It was difficult.

  On the other hand, when masking is performed using a resist coating photolithography method, it is possible to form fine holes, grooves, and the like as compared with the film sticking method. However, since the material of the photoresist is expensive, when the pattern of the entire outer shape of the cover glass for portable devices is formed using the photoresist, there is a problem that the manufacturing cost of the cover glass for portable devices is increased. . In particular, when the cover glass for a mobile device is provided in a mobile device having a large display screen, the higher dimension of the total area of the photoresist necessary for forming a pattern of the entire outer shape of the cover glass for the mobile device. This problem has become apparent because the area of the portion that does not require accuracy is formed large. Furthermore, when the shape of the cover glass for portable devices does not have a hole, the area of a portion that does not require high dimensional accuracy tends to be further increased. Such a problem occurs not only in the cover glass for portable devices but also in the cover glass for touch sensors.

  Then, an object of this invention is to provide the manufacturing method of the cover glass for electronic devices which can reduce the manufacturing cost of the cover glass for electronic devices, maintaining the dimensional accuracy of the cover glass for electronic devices.

The aspect of this invention is a manufacturing method of the cover glass for electronic devices.
The manufacturing method includes:
An etching step of etching the plate glass to obtain a glass substrate in the shape of the cover glass for electronic equipment by dissolving the plate glass along a processing pattern for forming the shape of the cover glass for electronic equipment A method of manufacturing a glass substrate for a cover glass for electronic equipment,
A non-photosensitive resist layer which forms a non-photosensitive resist layer made of a material having non-photosensitivity and etching resistance on the main surface of the plate-like glass so as to cover at least a part of the non-dissolved region in the etching step Forming process;
A photosensitive resist layer forming step of forming a photosensitive resist layer on the main surface of the sheet glass so as to cover a region including the dissolved region in the etching step and to be adjacent to the non-photosensitive resist layer;
A patterning step of forming the processed pattern on the photosensitive resist layer by exposing and developing the photosensitive resist layer;
And the etching step performed after the patterning step.

  In the said manufacturing method, it is preferable that one edge part of the said non-photosensitive resist layer and the said photosensitive resist layer is provided so that it may overlap with the other.

  In the manufacturing method, in the photosensitive resist layer forming step, the photosensitive resist layer is formed in a lattice shape on one main surface of the sheet glass, and in the etching step, the region of the one main surface It is preferable to form a plurality of outer shapes of the glass substrates so as to respectively include regions covered with the non-photosensitive resist layer.

In the manufacturing method, the photosensitive resist layer forming step is preferably performed before the non-photosensitive resist layer forming step.
In the above manufacturing method, the non-photosensitive resist layer forming step may be performed before the photosensitive resist layer forming step.

  In the manufacturing method, the non-photosensitive resist layer is made of a resist or a film mainly composed of acrylic resin (PMMA), epoxy resin, polypropylene resin, polyvinyl chloride resin, polyethylene resin, polyimide resin, and the photosensitive resist layer. The layer is preferably made of a photoresist mainly composed of acrylic resin (PMMA).

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing cost of the cover glass for electronic devices with favorable dimensional accuracy can be reduced.

The perspective view of the cover glass for portable devices of this embodiment. The top view of the glass substrate used for the cover glass for portable devices. Sectional drawing which follows the AA line shown in FIG. (A) is a top view of plate glass, (b) is a top view of plate glass after a photoresist layer formation process. (A)-(c) is a principal part enlarged view which shows the process of forming a resist pattern and a non-photosensitive resist layer in order with respect to the plate-like glass shown in FIG.4 (b). (A)-(c) is sectional drawing which shows the process of forming the external shape of a glass substrate in order using an etching. Sectional drawing which shows the modification of the process shown to Fig.6 (a). (A), (b) is sectional drawing which shows the modification of the process shown to Fig.5 (a), (c).

(1) The cover glass for portable devices of this embodiment The structure of the cover glass for portable devices of this embodiment (henceforth a cover glass) is demonstrated with reference to FIGS. FIG. 1 is a perspective view of a cover glass of the present embodiment, FIG. 2 is a plan view of a glass substrate used for the cover glass, and FIG. 3 is a cross-sectional view taken along line AA shown in FIG. In the following, a cover glass for a portable device will be described as a cover glass for an electronic device, but the present invention can also be applied to a cover glass for a touch sensor used as a cover member for an internal substrate in the touch sensor.

  The cover glass of the present embodiment is, for example, a portable device capable of performing an operation input (operation input as a touch panel function) on a display screen, particularly a portable device such as a mobile phone, a PDA, a digital still camera, a video camera, or a slate PC. Used to protect display screens and circuit boards. For this reason, the cover glass needs to be thin and high-strength glass in order to satisfy the specifications for dropping or operating input to the display screen. Therefore, it is preferable that the cover glass is chemically strengthened by ion exchange treatment. .

  As shown in FIGS. 1-3, the cover glass of this embodiment is formed in plate shape, and the main surface (the 1st main surface 11 and the 2nd main surface 12 which are mentioned later) of the glass substrate 10 which comprises a cover glass. ) Is formed in, for example, a substantially rectangular shape having a longitudinal dimension of 8 to 16 cm and a lateral dimension of 4 to 8 cm. In addition, the shape of the main surface of the glass substrate 10 is not limited to a substantially rectangular shape or a rectangular shape, and may be appropriately changed according to the shape and structure of various portable devices.

  The thickness T of the glass substrate 10 is not particularly limited, but it is usually preferably 1 mm or less from the viewpoint of suppressing an increase in the weight of various portable devices using cover glass and reducing the thickness of the portable device. More preferably, it is 7 mm or less. In addition, it is preferable that the lower limit value of the plate thickness T is 0.2 mm or more from the viewpoint of ensuring the mechanical strength of the cover glass.

  The glass substrate 10 is formed to be attachable to the casing of the portable device so as to cover the display screen of the portable device. The glass substrate 10 has a first main surface 11 that faces the outside of the portable device when attached to the casing of the portable device, and a first main surface 11 that faces the display screen of the portable device when attached to the display screen of the portable device. 2 main surfaces 12. In addition, in order to suppress the position shift at the time of attaching a cover glass to the housing | casing of a portable apparatus and to fit appropriately, the outer periphery of the 1st main surface 11 and the 2nd main surface 12 is a high dimension in the patterning process mentioned later. The pattern is preferably formed with accuracy (for example, about 5 to 20 μm).

  As shown in FIG. 3, the first main surface 11 and the second main surface 12 oppose each other in the plate thickness direction (Z direction in the drawing) of the glass substrate 10. The first main surface 11 has a central part 11a (a part surrounded by a broken line in FIG. 2) and a peripheral part 11b (a part other than the central part 11a in the first main surface 11 in FIG. 2). . The central portion 11a is a portion that overlaps the display area of the display screen of the mobile device when the cover glass is attached to the housing of the mobile device. The shape and position of the central portion 11a may be appropriately changed according to the shape and position of the display area of the display screen. Moreover, the 2nd main surface 12 has the center part 12a and the peripheral part 12b (all are shown in FIG. 3) similarly to the 1st main surface 11. FIG. In addition, since center part 11a, 12a of each main surface 11 and 12 is a part which overlaps with the display area of a display screen, a shape and a hole process are not required. For this reason, the central portions 11a and 12a do not have to be patterned with the same dimensional accuracy as the outer circumferences of the main surfaces 11 and 12 in the patterning step.

  The peripheral edge portion 11b of the first main surface 11 is provided with a voice input / output hole 13 of a speaker or a microphone, for example. As shown in FIG. 3, the hole 13 is formed so as to penetrate the glass substrate 10 in the plate thickness direction. The arrangement position of the hole 13 may be appropriately changed according to the arrangement position of the speaker or the microphone, for example. Note that the hole 13 is formed with high dimensional accuracy in the patterning process in order to prevent positional displacement between the speaker or microphone and the hole 13 when the glass substrate 10 is attached to the casing of the portable device. A pattern is preferably formed.

  In addition, the shape of the opening surface 13a of the hole 13 (the surface that is coplanar with the first main surface 11 or the second main surface 12) is appropriately changed according to the shape of the speaker or microphone on the surface of the casing of the portable device. May be.

  A shielding part (not shown) for shielding light that is about to enter the glass substrate 10 may be provided at the peripheral edge part 11 b of the first main surface 11 or the peripheral edge part 12 b of the second main surface 12. When providing a shielding part, you may form a shielding part by laminating | stacking a coating material in multiple layers, for example.

  Furthermore, the glass substrate 10 may be provided with a recess (including a groove) that is recessed from one main surface to the other main surface of the pair of main surfaces 11 and 12. For example, the recess may be for fitting with a casing of a mobile device, or may be for providing a shielding unit, a touch panel module, or the like. Further, the recess may be formed in a cutout shape from the one main surface to the side surface (outer peripheral end surface) of the glass substrate 10, or from the side surface of the glass substrate 10 to the inside in the surface direction of the one main surface. It may be formed at intervals. The concave portion may be a concave portion that can be recognized as a character or a figure when viewed from the front side of the portable device, or a concave portion that can be recognized when touched from the front side of the portable device.

  A compressive stress layer having a predetermined thickness may be formed on each of the pair of main surfaces 11 and 12 of the glass substrate 10 by chemical strengthening described later. This compressive stress layer is an altered layer in which a part of the alkali metal originally contained in the glass material constituting the glass substrate 10 is replaced with an alkali metal having a larger ionic radius. For example, it substitutes for sodium ions or potassium ions contained in the glass material constituting the glass substrate 10 of the present embodiment.

The glass substrate 10 of this embodiment is preferably composed of, for example, aluminosilicate glass, soda lime glass, borosilicate glass, or the like. Among these, the glass substrate 10 is made of an aluminosilicate glass containing SiO ₂ , Al ₂ O _3, and at least one alkali metal oxide selected from Li ₂ O and Na ₂ O. preferable.

(2) Manufacturing method of cover glass of embodiment Next, the manufacturing method of the cover glass of this embodiment is demonstrated with reference to FIGS. 4 (a) is a plan view of the sheet glass, FIG. 4 (b) is a plan view of the sheet glass after the photoresist layer forming step, and FIGS. 5 (a) to 5 (c) are shown in FIG. 4 (b). The principal part enlarged view which shows the process of forming a resist pattern and a non-photosensitive resist layer with respect to the plate-shaped glass in order, FIG.6 (a)-(c) is the process of forming the external shape of a glass substrate using an etching. FIG.

(2-1) Sheet Glass Production Process The sheet glass production process is a process for producing a sheet glass 100 (shown in FIG. 4A) from molten glass, and for example, a float method can be adopted. The float process is a method in which molten glass melted in a melting furnace is supplied to a float bath in which molten tin is stored, and the molten glass is drawn on the molten tin in the float bath in the horizontal direction and molded. According to the float method, the molten glass floats on the molten tin of the float bath, and the molten glass naturally spreads to a stable thickness. Molded. And a glass ribbon is cut | disconnected so that the plate-shaped glass 100 of a desired magnitude | size may be obtained after being conveyed to the slow cooling furnace provided in the downstream of the float bath, and cooling slowly.

  As a method for producing the plate glass 100, a downdraw method, a press method, or the like may be used in addition to the float method. Here, it is preferable to use the float method from the point that the plate-like glass 100 with good surface accuracy is obtained and the point that the plate-like glass 100 is suitable for mass production.

  The plate-like glass 100 produced in the present embodiment has, for example, a dimension in the longitudinal direction (X direction in FIG. 4A) of 30 to 100 cm and a dimension in the lateral direction (Y direction in FIG. 4A). It is formed in a substantially rectangular shape of 30 to 100 cm. The dimensions of the plate glass can be set arbitrarily, and may be set based on the viewpoints of convenience of handling during transportation and manufacturing, manufacturing efficiency, and the like. Further, the sheet glass 100 has a pair of main surfaces (a first main surface 101 and a second main surface 102) that face each other in the plate thickness direction. Here, the first main surface 101 of the sheet glass 100 corresponds to the first main surface 11 of the glass substrate 10. Further, the second main surface 102 of the plate glass 100 corresponds to the second main surface 12 of the glass substrate 10. In addition, the part shown with the broken line in FIG. 4 (a), (b) and FIG. 5 (a) has shown the 1st main surface 11 of each of the several glass substrate 10 obtained from the sheet glass 100. FIG.

(2-2) Shape processing step Next, a shape processing step is performed. A shape processing process is a process of forming the external shape of the several glass substrate 10 from the plate glass 100 produced at the plate glass production process. The shape processing step includes the following (a-1) photoresist layer forming step, (a-2) patterning step, (a-3) non-photosensitive resist layer forming step, and (a-4) etching step.

  By using etching in the shape processing step, it is possible to suppress the occurrence of minute scratches, microcracks, and the like on the cut surface of the cover glass as compared with the case where the outer shape of the glass substrate is formed using machining. For this reason, it can prevent that the intensity | strength of a cover glass falls due to a micro crack, a micro crack, etc.

  In the shape processing step, a photoresist layer 110 and a non-photosensitive resist layer 120, which will be described later, may be formed on both surfaces of the pair of main surfaces 101 and 102 of the glass sheet 100. When only the main surface is brought into contact with the etching solution, it may be formed only on the one main surface. In the following description, it is assumed that the photoresist layer 110 and the non-photosensitive resist layer 120 are formed on both surfaces of the pair of main surfaces 101 and 102 of the sheet glass 100.

(A-1) Photoresist layer (photosensitive resist layer) forming step In the photoresist layer forming step, a partial region (second region R2 described later) of each of the main surfaces 101 and 102 of the sheet glass 100 is covered. Thus, a photoresist layer (etching resistant layer) 110 is formed. Here, the partial region is a region including a dissolved region that is dissolved in the etching process. By forming the photoresist layer 110 in a partial region of each of the main surfaces 101 and 102, an expensive material is included as compared with the case where the photoresist layer 110 is formed on the entire surface of each of the main surfaces 101 and 102. The amount of photoresist used can be reduced. For this reason, the manufacturing cost of a cover glass can be reduced. Further, since a part of each of the main surfaces 101 and 102 can be masked using a resist coating photolithography method, a minute hole or groove can be formed in the part of the part. it can.

  The photoresist layer 110 has a property (etchant resistance) that can be partially removed by a patterning process in a later patterning process and is not dissolved or removed by an etching solution used in the etching process. It can be selected as appropriate. As such a photoresist layer 110, it is preferable to use a photoresist that is at least insoluble or insoluble in an aqueous hydrofluoric acid solution. For example, an acrylic resin (PMMA: Polymethyl methacrylate) is preferably used as a main component.

  The photoresist layer 110 may be formed by using, for example, a screen printing method, a coating method, a dipping method, a cap coating method, or the like. Here, the screen printing method is a method in which a screen on which a predetermined pattern is formed depending on the presence / absence of an opening is placed on each main surface 101, 102, and a photoresist is passed through the opening, thereby allowing each main surface 101, 102 to pass. In this method, a photoresist layer 110 is formed thereon. The coating method is a method of forming a photoresist layer 110 on each main surface 101, 102 by applying a photoresist solution to each main surface 101, 102 using a brush or the like. Further, the dipping method is a method of forming the photoresist layer 110 on the main surfaces 101 and 102 by immersing the main surfaces 101 and 102 in a photoresist solution. Furthermore, the cap coat method is a method of forming a photoresist layer 110 on each main surface 101, 102 by attaching a photoresist solution to each main surface 101, 102 using a capillary phenomenon.

  Here, the screen printing method is preferable in terms of the positional accuracy of the formed photoresist layer on the plate-like glass surface. The cap coat method is preferable in that it can be partially applied.

  An example of the sheet glass 100 after the photoresist layer forming step is shown in FIG. As shown in FIG. 4B, the photoresist layer 110 is preferably formed in a lattice pattern on the first main surface 101 and / or the second main surface 102. Thereby, compared with the case where the photoresist layer 110 is formed in the whole surface of the 1st main surface 101 and / or the 2nd main surface 102, the usage-amount of a photoresist can be reduced. In particular, when the area ratio between the first region R1 and the second region R2, which will be described later, the area of R1 / (the area of R1 + the area of R2) is large, the amount of photoresist used can be further reduced.

Here, the reduction in the amount of use of the above-described photoresist is calculated using a rectangular shape having a long side of 80 mm and a short side of 60 mm as an example. The cutting width W1 (shown in FIG. 6 (a)) necessary for forming the outer shape of the glass substrate by etching is 2 mm, the outer shape forming pattern, the protective film made of a material other than the adjacent photoresist, and the outer shape processing pattern. When a photoresist pattern having a total width W2 (shown in FIG. 6 (a)) of 2 mm (one side, 4 mm on both sides) is required to form a glass substrate. Is (80 + 2) × (60 + 2) − (80−4) × (60−4) = 828 mm ² . Since the area required for forming one glass substrate including a cutting width of 2 mm (1 mm on one side and 2 mm on both sides) is (80 + 2) mm × (60 + 2) mm = 5084 mm ² , the amount of photoresist used is 828/5084 = 0. .16 and a calculation that can be reduced by about 84%.

  In FIG. 4B, a plurality of regions (first regions) R1 partitioned by the photoresist layer 110 are regions where the non-photosensitive resist layer 120 is formed in the subsequent non-photosensitive resist layer forming step. is there. Each of the plurality of first regions R1 may be formed so as to include all of the central portion 11a of the first main surface 11 of the glass substrate 10, as shown in FIG.

  The region (second region) R2 where the photoresist layer 110 is formed is formed so as to include the peripheral edge portion 11b of the glass substrate 10 to be manufactured. Thereby, the peripheral part 11b of the 1st main surface 11 of the glass substrate 10 can be formed by performing the masking using the resist coating photolithography method. For this reason, since the part (for example, the outer periphery of the 1st main surface 11, the hole 13, etc.) where high dimensional accuracy is requested | required in the peripheral part 11b can be pattern-formed with high dimensional accuracy, a cover glass with favorable dimensional accuracy is used. Can be produced.

(A-2) Patterning step In the patterning step, masking using a photolithography method is performed. Specifically, a desired resist pattern is formed by exposing and developing the photoresist layer 110. In the patterning step, as shown in FIG. 5B, among the photoresist layer 110 formed in the second region R2, the photoresist layer 110 other than the region corresponding to the outer shape of the glass substrate 10 to be fabricated (FIG. 5). In the example shown in (b), the white background portion of the edge of the glass substrate is removed. At this time, a pattern hole 111 corresponding to the hole 13 of the glass substrate 10 is formed. When the photoresist layer 110 is formed on both the main surfaces 101 and 102 of the sheet glass 100, the patterning process may be performed on at least one of the main surfaces 101 and 102. May be implemented. Alternatively, a photoresist layer 110 may be formed on the main surface 101 of the plate glass 100 and patterning may be performed on the main surface 101.

(A-3) Non-photosensitive resist layer forming step In the non-photosensitive resist layer forming step, as shown in FIG. A non-photosensitive resist layer 120 is formed so as to cover one region R1). Here, the partial region is a region including at least a part of a region that is not dissolved in the etching process (non-dissolved region). Further, as shown in FIG. 5C, the non-photosensitive resist layer 120 is formed so as to be adjacent to the photoresist layer 110. As will be described later, the non-photosensitive resist layer 120 has etchant resistance and is made of a material different from the photoresist. Here, 1st area | region R1 is an area | region including the center part 11a of the 1st main surface 11 of the glass substrate 10 produced, ie, the area | region including the part in which high dimensional accuracy is not essential in the glass substrate 10. FIG. Therefore, even if masking is performed on the first region R1 using the non-photosensitive resist layer 120 made of a material different from the photoresist, a cover glass with good dimensional accuracy can be produced. .
In FIG. 5C, a region where the non-photosensitive resist layer 120 or the photoresist layer 110 is not formed (a white portion in the drawing) is a region (dissolved region) that is dissolved in the etching process. .

  Further, in the non-photosensitive resist layer forming step, it is preferable that the edge 120a (FIG. 6A) of the non-photosensitive resist layer 120 is provided so as to overlap the upper surface of the photoresist layer 110. Thereby, when the first main surface 101 of the sheet glass 100 is viewed in the normal direction, the boundary between the non-photosensitive resist layer 120 and the photoresist layer 110 is covered with the non-photosensitive resist layer 120. In a subsequent cutting step, the etching solution can be prevented from entering the boundary between the non-photosensitive resist layer 120 and the photoresist layer 110. For this reason, it is possible to prevent the first main surface 101 of the glass sheet 100 from being dissolved at the boundary between the non-photosensitive resist layer 120 and the photoresist layer 110.

  The non-photosensitive resist layer 120 is preferably formed by using a screen printing method or a laminate film processing method. Here, when the screen printing method is used, the non-photosensitive resist layer 120 may be formed using a resist having a lower price than the photoresist. Thereby, compared with the case where the photoresist layer 110 is formed on the entire surface of the first main surface 101, the amount of the photoresist used can be reduced. Therefore, the manufacturing cost of the cover glass can be reduced.

  The non-photosensitive resist layer 120 is appropriately selected as long as it has a property (etchant resistance) that is not dissolved / removed in an etching solution used in a subsequent etching process and is made of a material different from the photoresist. You can choose. By selecting a material different from the photoresist as the non-photosensitive resist 120, the amount of the photoresist used can be reduced and the manufacturing cost of the cover glass can be reduced. Therefore, the non-photosensitive resist 120 is preferably made of, for example, a resist or film mainly composed of acrylic resin (PMMA), epoxy resin, polypropylene resin, polyvinyl chloride resin, polyethylene resin, or polyimide resin.

  The non-photosensitive resist layer 120 is preferably subjected to heat treatment and light irradiation treatment as necessary.

(A-4) Etching Step In the etching step, the first main surface 101 provided with the patterned photoresist layer 110 and the non-photosensitive resist layer 120 is etched by contacting with the etching solution. At this time, the glass substrate in the shape of the cover glass is obtained by melting the plate glass along the processing pattern for forming the shape of the cover glass. The etching process is usually performed by showering the etching solution in the plate glass 100 or immersing the plate glass in the etching solution. The etching solution is not particularly limited as long as it contains at least hydrofluoric acid. If necessary, other acids such as hydrochloric acid and various additives such as a surfactant may be added.

  A method for forming the outer shapes of the plurality of glass substrates 10 using etching on the first main surface 101 and the second main surface 102 of the plate glass 100 will be described with reference to FIG. FIG. 6 shows a case where the shape processing step is performed on both the first main surface and the second main surface. FIG. 6A is a cross-sectional view of the sheet glass 100 after the non-photosensitive resist layer forming step. First, wet etching is performed using an etching solution (for example, an acidic solution containing hydrofluoric acid) capable of dissolving a glass material, using the photoresist layer 110 and the non-photosensitive resist layer 120 on which a resist pattern is formed as a mask. Examples of the acidic solution containing hydrofluoric acid include a hydrofluoric acid aqueous solution, a mixed solution of hydrofluoric acid and hydrochloric acid, a mixed solution of hydrofluoric acid and sulfuric acid, and an aqueous solution containing ammonium fluoride.

At this time, a portion including a region (dissolved region) where the non-photosensitive resist layer 120 or the photoresist layer 110 is not formed in the region of the first main surface 101 and the second main surface 102 is etched. Thereby, the hole 13 of the glass substrate 10 is formed (refer FIG.6 (b)). Further, a portion including the region (non-dissolved region) where the non-photosensitive resist layer 120 or the photoresist layer 110 is formed in the region of the first main surface 101 and the second main surface 102 is along the outer periphery of the resist pattern. By cutting out from the sheet glass 100, the outer shape of the glass substrate 10 is formed.
Then, the remaining non-photosensitive resist layer 120 and the photoresist layer 110 are peeled and washed (see FIG. 6C).

In this way, the outer shape of the glass substrate 10 is formed.
As shown in FIG. 4B, when the photoresist layer 110 is formed in a lattice shape, the plurality of glass substrates 10 are formed so as to include the first regions partitioned by the photoresist layer 110, respectively. An outline is formed.

(2-3) Chemical strengthening process Next, a chemical strengthening process is performed with respect to the glass substrate 10 obtained by the shape processing process.
In the chemical strengthening step, a plurality of glass substrates 10 are loaded into a cassette (holder), and the cassette is immersed in a chemical strengthening treatment liquid containing a molten salt. Thereby, one or more kinds of alkali metals contained in the glass substrate 10 are subjected to ion exchange treatment with the alkali metal of the molten salt, and a compressive stress layer is formed on the surface layer portion of the glass substrate 10.

  The composition and temperature of the molten salt, and the immersion time can be appropriately selected according to the glass composition of the glass substrate 10, the thickness of the compressive stress layer formed on the surface layer portion of the glass substrate 10, and the like. If it is the aluminosilicate glass mentioned above, it is preferable to utilize the low temperature type ion exchange method which makes the process temperature of a chemical strengthening process liquid normally 300 to 500 degreeC.

For example, in the chemical strengthening step of the present embodiment, the composition and temperature of the molten salt and the immersion time are preferably selected from the ranges exemplified below.
Composition of molten salt: simple salt of potassium nitrate (KNO ₃ ), simple salt of sodium nitrate (NaNO ₃ ), or mixed salt in which potassium nitrate and sodium nitrate are mixed at an arbitrary weight ratio Temperature of molten salt: 350 ° C. to 450 ° C
・ Immersion time: 1-8 hours

The thickness of the compressive stress layer formed on each of the main surfaces 11 and 12 of the glass substrate 10 by this chemical strengthening process is 5 to 80 μm. In this embodiment, since the glass composition of the glass substrate 10 is an aluminosilicate glass, the thickness of the compression stress layer formed is increased when compared with, for example, soda lime float glass having the same plate thickness as the glass substrate 10. can do.
Incidentally, the mechanical strength of the glass substrate 10 obtained by the chemical strengthening process, preferably 5000 kgf / cm ² or more in three-point bending strength (3-point bending strength), more preferably, 7000kgf / cm ² or more, most Preferably, it is 10,000 kgf / cm ² or more.

Thus, the cover glass of this embodiment is obtained.
In addition, when forming a shielding part in the peripheral part (peripheral part 11a or peripheral part 11b) of any one main surface of the chemically strengthened glass substrate 10, the printing process for forming a shielding part is performed. Also good. For the printing method, various known methods such as screen printing can be used according to the paint constituting the printing layer and the thickness of each layer of the printing layer. Here, as the paint, for example, various inks using carbon as a pigment can be used.

  As described above, according to the cover glass manufacturing method of the present embodiment, the non-photosensitive material made of a material having non-photosensitive property and etching resistance so as to cover at least a part of the non-dissolved region in the etching process. A non-photosensitive resist layer forming step for forming the resist layer 120 on the first main surface 101 and the second main surface 102 of the plate-like glass 100, and a non-photosensitive resist layer 120 covering a region including a dissolved region in the etching step A photoresist layer forming step of forming a photoresist layer 110 on the first main surface 101 and the second main surface 102 of the sheet glass 100 so as to be adjacent to each other, and exposing and developing the photoresist layer 110 A patterning process for forming a processed pattern on the photoresist layer 110 and an etching process performed after the patterning process. To have. Thereby, compared with the case where the photoresist layer 110 is formed in the whole surface of each of the 1st main surface 101 and the 2nd main surface 102, the usage-amount of a photoresist can be reduced. Therefore, the manufacturing cost of the cover glass can be reduced.

  Further, according to the cover glass manufacturing method of the present embodiment, since the photoresist layer 110 is formed in the second region R2 including the peripheral edge portion 11b of the glass substrate 10, the peripheral edge portion 11b is formed by resist coating photolithography. It can form by performing masking using. For this reason, since the part (for example, the outer periphery of the 1st main surface 11, the hole 13, etc.) where high dimensional accuracy is required can be formed with high dimensional accuracy in the peripheral part 11b, a cover glass with favorable dimensional accuracy is produced. can do.

  Furthermore, according to the manufacturing method of the cover glass of this embodiment, the glass substrate 10 is cut out from the plate glass 100 by using etching. Thereby, compared with the case where a glass substrate is cut out from sheet glass using machining, generation | occurrence | production of the fine damage | wound, a micro crack, etc. in the cut surface of a cover glass can be suppressed. For this reason, it can prevent that the intensity | strength of a cover glass falls due to a micro crack, a micro crack, etc.

  In addition, according to the cover glass manufacturing method of this embodiment, since the non-photosensitive resist layer 120 is formed after the photoresist layer 110 is formed on the plate-like glass 100, the non-photosensitive resist layer 120 is formed. Is easy to position. This becomes more prominent when the non-photosensitive resist layer 120 is a film sticking method. When forming a photoresist layer after the formation of the non-photosensitive resist layer 120 by the film sticking method, it is difficult to position because there is no positioning marking when the film is first attached to the sheet glass 100. Become.

  Further, when the non-photosensitive resist layer 120 is formed by using a film sticking method after the formation of the photoresist layer 110, non-photosensitive in consideration of the adhesion between the photoresist layer 110 and the adhesive of the film. An adhesive material for the conductive resist layer 120 can be selected. On the other hand, when the photoresist layer 110 is formed after the formation of the non-photosensitive resist layer 120 (formed using a film sticking method), the adhesion between the film substrate and the photoresist layer 110 is good (does not repel). ). In this case, there are cases where a film based on a fluororesin having a low surface energy cannot be used.

(3) Modified Examples Hereinafter, modified examples of the above-described embodiment will be described.
(3-1) Modification 1
Modification 1 of the above-described embodiment will be described with reference to FIG. FIG. 7 is a cross-sectional view showing a modification of the process shown in FIG. In this modification, in the shape processing step, (a-3) a non-photosensitive resist layer forming step, (a-1) a photoresist layer forming step, (a-2) a patterning step, and (a-4) a cutting step. Shape processing is performed in order. Also in this modified example, the amount of photoresist used can be reduced as compared with the case where the photoresist layer 110 is formed on the entire surface of the first main surface 101 as in the above embodiment. Therefore, the manufacturing cost of the cover glass can be reduced.

  Further, by performing the non-photosensitive resist layer forming step before the photoresist layer forming step, the edge 110a of the photoresist layer 110 overlaps the upper surface of the non-photosensitive resist layer 120 as shown in FIG. Is provided. Thereby, when the first main surface 101 of the glass sheet 100 is viewed in the normal direction, the boundary between the non-photosensitive resist layer 120 and the photoresist layer 110 is covered by the edge portion 110a of the photoresist layer 110. In a subsequent cutting step, the etching solution can be prevented from entering the boundary between the non-photosensitive resist layer 120 and the photoresist layer 110. For this reason, it is possible to prevent the first main surface 101 of the glass sheet 100 from being dissolved at the boundary between the non-photosensitive resist layer 120 and the photoresist layer 110.

(3-2) Modification 2
A modification of the above-described embodiment will be described with reference to FIG. 8A and 8B are cross-sectional views showing a modification of the process shown in FIGS. 5A and 5C. In the shape processing step, a plurality of first regions R1 may be formed in the first main surface 11 of the glass substrate 10 to be manufactured, as shown in FIG. In this case, each of the plurality of first regions R1 is formed so as to include a part of the central portion 11a of the first main surface 11, and the non-photosensitive resist layer 120 is formed as shown in FIG. 8B. Is done. Also in this modified example, the amount of photoresist used can be reduced as compared with the case where the photoresist layer 110 is formed on the entire surface of the first main surface 101 as in the above embodiment. Therefore, the manufacturing cost of the cover glass can be reduced.

  As mentioned above, although embodiment of this invention was described in detail, the cover glass for electronic devices of this invention, its manufacturing method, and the touch sensor module for electronic devices are not limited to the said embodiment, and do not deviate from the main point of this invention. Of course, various improvements and changes may be made in the range.

DESCRIPTION OF SYMBOLS 10 ... Glass substrate 11 ... 1st main surface 12 ... 2nd main surface 13 ... Hole 100 ... Sheet glass 101 ... 1st main surface 102 ... 2nd main surface 110 ... Photoresist layer 110a ... Edge part 120 ... Non-photosensitive Resist layer 120a ... edge R1 ... first region R2 ... second region

Claims (6)

An etching step of etching the plate glass to obtain a glass substrate in the shape of the cover glass for electronic equipment by dissolving the plate glass along a processing pattern for forming the shape of the cover glass for electronic equipment A method of manufacturing a glass substrate for a cover glass for electronic equipment,
A non-photosensitive resist layer which forms a non-photosensitive resist layer made of a material having non-photosensitivity and etching resistance on the main surface of the plate-like glass so as to cover at least a part of the non-dissolved region in the etching step Forming process;
A photosensitive resist layer forming step of forming a photosensitive resist layer on the main surface of the sheet glass so as to cover a region including the dissolved region in the etching step and to be adjacent to the non-photosensitive resist layer;
A patterning step of forming the processed pattern on the photosensitive resist layer by exposing and developing the photosensitive resist layer;
The etching step performed after the patterning step;
The manufacturing method of the cover glass for electronic devices characterized by including. One edge of the non-photosensitive resist layer and the photosensitive resist layer is provided to overlap the other,
The manufacturing method of the cover glass for electronic devices of Claim 1. In the photosensitive resist layer forming step, the photosensitive resist layer is formed in a lattice shape on the main surface of the sheet glass,
In the etching step, the outer shapes of the plurality of glass substrates are formed so as to include the regions covered with the non-photosensitive resist layer among the regions of the main surface,
The manufacturing method of the cover glass for electronic devices of Claim 1 or 2. The photosensitive resist layer forming step is performed before the non-photosensitive resist layer forming step.
The manufacturing method of the cover glass for electronic devices of any one of Claims 1-3. The non-photosensitive resist layer forming step is performed before the photosensitive resist layer forming step.
The manufacturing method of the cover glass for electronic devices of any one of Claims 1-3. The non-photosensitive resist layer is made of a resist or film mainly composed of acrylic resin (PMMA), epoxy resin, polypropylene resin, polyvinyl chloride resin, polyethylene resin, polyimide resin, and the photosensitive resist layer is made of acrylic resin. A photoresist mainly composed of (PMMA),
The manufacturing method of the cover glass for electronic devices of any one of Claims 1-5.

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